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Post by zyrobs on Oct 19, 2021 6:54:33 GMT
You need a native scart cable that is wired for NTSC Saturns.
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Post by zyrobs on Oct 17, 2021 20:51:06 GMT
Seems to be based on SSF 90's emulator. Based on the ini files posted there, it seems to be a fairly recent version of the Android version of SSF (which still gets updated, to this very day).
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Post by zyrobs on Oct 14, 2021 14:36:08 GMT
I doubt it's the low ram giving you the problems, since you don't get any sound whatsoever. But for a test you could just remove both of those ram chips and exchange them.
You can check the schematics to see which pin connects to where. Then use your multimeter in continuity mode to test if they actually make a connection. It is possible there's a broken trace UNDER one of the chips that you don't see. That and a broken sound clock are my best guesses - check IC24 pin 2 (or TP21) which should read 22.58 MHz (this is the SCSP clock), and IC24 pin 10 or TP22, which should read half of that (this is the 68000 sound cpu clock). If your multimeter can measure DC frequency, that should be enough for checking the clocks, assuming it can read as high as these values.
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Post by zyrobs on Oct 12, 2021 13:09:27 GMT
The rest of the crystals shouldn't cause an issue, the problem is interference with the signal generated by X1. Unfortunately we don't know much more about the problem, someone with a scope would need to analyse the nature of the error, but I've got a feeling that it's simply the PLL chip dying.
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Post by zyrobs on Oct 12, 2021 12:57:04 GMT
I'd check if all the contacts in the cable have continuity in them.
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Post by zyrobs on Oct 11, 2021 11:46:32 GMT
What would cause a trace to get damaged if the system was never opened before? It didn't appear to be anyway. I'll have to find a component map of the board and start checking traces between components you mentioned. Recapping, some surface mount stuff here and there, swapping a couple IC chips is stuff I'm confident with..... This sounds like it may be beyond my capability to repair but would be nice if I found something simple or obvious...you never know lol The pcb can just break down over time due to contact with air, depending on air quality and potential flaws. A while ago a guy had a broken trace that caused video glitches, and the broken trace happened to be under one of the qfp chips. So, it can happen. Checking whether all pins are connected to where they should be is a very good start for troubleshooting. Here's hoping you find the culprit that way.
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Post by zyrobs on Oct 11, 2021 2:17:53 GMT
Wait, I just noticed that part where you say you have NO SOUND. Does that mean there's not even any jingles when you set the date? That would mean that something on the sound side is broken.
First up I'd check if the clock signals connect right. There should be service manuals available online for the PAL VA0 unit which is largely the same other than some jumpers, you can use that as a reference for which pins to check. If your multimeter can check frequencies, you should also be able to measure the signal, it's not as informative as using a scope but you'll at least be able to check if there's a proper clock in there or not.
If you are lucky, it's just a broken trace connecting the 68k, SCSP, and sound memory together and with the rest of the system - the trace may be under those ICs, so you could consider desoldering them and inspecting the board. Or the sound memory is broken. I'd try switching it out with one of the work ram low chips, I think they are the same type, 512k and same j-wing packaging. That should at least confirm if the issue is that, the console can boot without the work ram low but it won't get too far in games.
I think, in that case, the SH1 sub-board should not be a culprit. But if memory serves, the sound clock is derived from the clock the system receives from the CD drive, so removing it may shake things up enough for the system to behave differently.
Also, try holding the blue button next to the battery. That will reset the memory and date completely. It might help if something was dodgy there, but I think the issue is with the sound subsystem side of things.
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Post by zyrobs on Oct 11, 2021 2:02:20 GMT
If you remove it and it behaves different, then it is possible that something on the SH1 side does not work. Of course it's also possible that something that tries to communicate with the SH1 is having a fault. But on VA0.5 motherboards, the SH1 sub-board is removable, so it would take no time at all to check that.
Many IC programmers have the ability to test logic chips. RAM testing is a bit trickier, but there are tools for that too. You also need adapters since most things on the Saturn are SOP, while testers are for DIP packages. The thing is that unless you regularly repair stuff, a tester is not worth the cost because it is simpler to just buy replacement 74xx components, or even a new Saturn altogether.
Problem is that if your Saturn can show up the date selection without glitches (and playing sound), then the majority of the system is already working fine - the two video chips, all the VDP1 memory, the boot rom, at least one of the VDP2 memory banks, the master SH2 and the work ram high must definitely be working. Work ram low is not used on the bootup process, and I think the slave sh2 is unused too. If you get proper sound on the date selection, then the entire sound subsystem is also working correctly. SCU must be working since it handles nearly all data transfers, but the DSP inside is a toss-up (it is used during the animation but only for something trivial). The clock signals generated by the PLL must all be good too, otherwise most of the system just would not work.
That leaves the SH1 sub board, the SRAM chip, the DCC which communicates with the SRAM, and the RTC clock part of the SMPC.
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Post by zyrobs on Oct 10, 2021 8:26:19 GMT
I finally got around to trying my Satiator today and.... I can't get it to work at all 🤦♂️ You should check the leds on the back of it, there's a list of different patterns somewhere. It turns out the MPEG connector sucks almost as much as the cartridge connector, so it's possible you have a bad connection. Or you are using it on a VA0 unit which had some BIOS issues (but these may have been fixed since I last checked).
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Post by zyrobs on Oct 10, 2021 8:21:31 GMT
Well you bought it junked, can't expect to repair everything.
I'd attempt to check the board for broken traces, then test all the logic components (the numerous 74 ICs) which would be easy to replace if they are bad. Then the memory, which is still replaceable... if it's none of those, it is an ASIC issue and in that case you need another dead unit as a donor. But, if you get as much as the date screen, then the CPU and graphics chips should be working right, and likely the sound too (if you get the jingles when setting the dates).
edit: What happens if you remove the SH1 sub-board and boot it like that? On a va0.5 you should have the 1.01 bios, so it should at least get into the CD player menu, with highly distorted sound (with the 1.00 bios, it just black screens if there's no SH1 sub-board or no cd drive connected).
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Post by zyrobs on Oct 5, 2021 23:30:33 GMT
Short of changing the crystals and the caps, not much. Changing the caps especially around the PLL area will help the setup get a more stable clock, but it seems the crystals are just getting too dodgy and the Saturn is extremely susceptible to that.
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Post by zyrobs on Oct 2, 2021 10:03:48 GMT
X2, but yeah. It's a 17.734475 MHz one in PAL machines. Should be easily available.
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Post by zyrobs on Oct 2, 2021 5:07:55 GMT
When I had the same issue, a recapping helped, but you still had to leave the console on for a while for it to "warm up". After which it worked fine for a longer time.
Another user mentioned that replacing the main crystal fixed the issue permanently. This would make sense since this is a clock issue, although I didn't knew that crystals can break down like that over time.
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Post by zyrobs on Oct 1, 2021 6:34:43 GMT
A 110V converter is fine, you don't need specifically a 100V or 120V one. Saturn PSUs are designed to handle way more AC voltage drift than that.
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Post by zyrobs on Sept 28, 2021 3:26:21 GMT
Region free bios.
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